package cn.tedu.sp06.fb;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.server.reactive.HttpHandler;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@Component//创建实例的权利交给spring容器
public class ItemFB implements FallbackProvider {
    /**
     * 设置针对那个后台服务降级 AFB BFB CFB DFB
     * -item-service:只针对商品服务降级
     * -*:对所有服务都应用当前降级类
     * -null:对所有服务都应用当前降级类
     *
     * @return
     */
    @Override
    public String getRoute() {
        return "item-service";
    }

    /*
    向客户端返回的响应数据
     */
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override//200 OK
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override//200
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override//OK
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {
                //用来关闭下面的流
                //BAIS(内存数组流)不占用底层系统资源,不需要关闭   需要关闭:文件系统  网络流  数据库的连接
            }

            @Override//要返回的协议体数据
            public InputStream getBody() throws IOException {
                //JsonResult - {code:500, msg:xxx, data:null}
                String json = JsonResult
                        .build()
                        .code(500)
                        .msg("(item)服务器内部错误!!!   稍后重试")
                        .toString();
                //字符串变成byte[]数组,封装到 BAIS(内存数组流)
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override//要返回的协议头数据
            public HttpHeaders getHeaders() {
                HttpHeaders h = new HttpHeaders();
                h.add("Content-Type", "application/json;charset=UTF-8");
                return h;
            }
        };
    }
}
